On the first attempt, the crew had difficulty moving the lever to the vertical position. They thought that to arm the hydrostatic hook release mechanism, they only had to move the lever to the vertical position and engage the stud in the groove of the housing. On the second attempt, the crew concentrated on properly engaging the long links of the falls in the hooks. The interlock device was not examined. Thinking they had cocked the interlock device because the lever was in the vertical position and the hook was engaged, the crew hoisted the lifeboat. The safety pin of the forward hook had not been replaced before the drill. Thus, the hook was engaged only by the interlock device. The presence of corrosion in the cable housing and the breaking of the metal cable hampered the cocking of the interlock device. Since the hook was not damaged, evidence indicates that the forward hook must have released from the interlock device. The force of gravity exerted by the hook on the partially cocked interlock device caused it to tip down. The hook pivoted, and the long link of the forward fall released from the hook.Analysis On the first attempt, the crew had difficulty moving the lever to the vertical position. They thought that to arm the hydrostatic hook release mechanism, they only had to move the lever to the vertical position and engage the stud in the groove of the housing. On the second attempt, the crew concentrated on properly engaging the long links of the falls in the hooks. The interlock device was not examined. Thinking they had cocked the interlock device because the lever was in the vertical position and the hook was engaged, the crew hoisted the lifeboat. The safety pin of the forward hook had not been replaced before the drill. Thus, the hook was engaged only by the interlock device. The presence of corrosion in the cable housing and the breaking of the metal cable hampered the cocking of the interlock device. Since the hook was not damaged, evidence indicates that the forward hook must have released from the interlock device. The force of gravity exerted by the hook on the partially cocked interlock device caused it to tip down. The hook pivoted, and the long link of the forward fall released from the hook. The monthly inspection did not include checking the hydrostatic hook release mechanism. The interlock device was not completely cocked before the lifeboat was hoisted back on board. The forward hook released during the lifeboat hoisting manoeuvre, causing the after hook to give way and resulting in the uncontrolled fall of the lifeboat. The crew members who were not wearing their hard hats suffered head injuries.Findings The monthly inspection did not include checking the hydrostatic hook release mechanism. The interlock device was not completely cocked before the lifeboat was hoisted back on board. The forward hook released during the lifeboat hoisting manoeuvre, causing the after hook to give way and resulting in the uncontrolled fall of the lifeboat. The crew members who were not wearing their hard hats suffered head injuries. The crew did not take all necessary actions to arm the hydrostatic hook release mechanism before hoisting the lifeboat back on board. The monthly inspection did not include checking the hydrostatic hook release mechanism. Thus, a safety pin was not replaced before the monthly abandon ship drill.Causes and Contributing Factors The crew did not take all necessary actions to arm the hydrostatic hook release mechanism before hoisting the lifeboat back on board. The monthly inspection did not include checking the hydrostatic hook release mechanism. Thus, a safety pin was not replaced before the monthly abandon ship drill. Following this occurrence, the release mechanisms on both the starboard and port lifeboats were inspected. As a result, the mechanism on the starboard lifeboat was overhauled under class supervision. The ship's training manuals and lifeboat launching instructions were amended to reflect the proper operation of the release mechanism and the importance of safety pins. The ship's maintenance manual was also amended to include a monthly inspection of the safety pins and a preventive maintenance program. In view of a trend evident from other incidents[2] involving faulty lifeboat release mechanisms, a TSB Marine Safety Information letter (MSI No.22/92) and a Marine Safety Advisory (MSA No.1/94) were forwarded to Transport Canada (TC). The latter suggested that TC promote an increased awareness among shipowners of the importance of preventive maintenance procedures for lifeboat release mechanisms. It was also suggested that TC ensure that adequate procedures for inspecting lifeboat release mechanisms are followed by its surveyors.Safety Action Taken Following this occurrence, the release mechanisms on both the starboard and port lifeboats were inspected. As a result, the mechanism on the starboard lifeboat was overhauled under class supervision. The ship's training manuals and lifeboat launching instructions were amended to reflect the proper operation of the release mechanism and the importance of safety pins. The ship's maintenance manual was also amended to include a monthly inspection of the safety pins and a preventive maintenance program. In view of a trend evident from other incidents[2] involving faulty lifeboat release mechanisms, a TSB Marine Safety Information letter (MSI No.22/92) and a Marine Safety Advisory (MSA No.1/94) were forwarded to Transport Canada (TC). The latter suggested that TC promote an increased awareness among shipowners of the importance of preventive maintenance procedures for lifeboat release mechanisms. It was also suggested that TC ensure that adequate procedures for inspecting lifeboat release mechanisms are followed by its surveyors.